Rocking type of drilling and tapping appliance for automatic lathes



Patented Sept. 25, 1951 APPLIANCE AUTOMATIC I AndrBechlei, Moutier, Switzerland. V

' Application Septem er 23, 1946, SerialNo.'698,81;3 j InSwitzerlandJune 17, 1 946 l I j a This invention-relates. odrilling and tapping appliances in automatic lathes.

In automatic lathes with a drilling and tapping appliance having a rocking tool holder, 1. e. an

appliance in which the tools are brought alternately into alignment-with the headstock spindle axis for drilling and tapping-of the work piece, the movement of, the tool holder is effected by a cam-driven lever carrying atoothed segment meshing with a pinion coupled with therocking tool holder. Should atool br'eak'off in the work piece, it is of the greatest "importance toprevent any damage to the control -mechanismand par- .ticularly if theaforesaid. lever driven by a grooved cam. a An object of my invention is to provide an appliance in which the said cam-driven lever is made in two pieces pivotally connected with each other and coupled by a clutch in such a manner that any relative displacement of the two pieces will disconnect the cam from the driving shaft.

Another object of my invention is to couple the two pieces of the cam-driven lever by a yieldable device which will be displaced by any accidental over-force and effect the above-mentioned relative displacement of the pieces. 7

Other objects and features will be apparent as the following description proceeds, reference being had to the accompanying drawings illustrating, by way of example, one embodiment of my invention, wherein:

Fig. 1 is a part sectional end elevation of the appliance as seen from the front end of the lathe, looking in the direction of the headstock spindle axis;

Fig. 2 is a plan view of the same, partly in section;

Fig. 3 is a side elevation, partly in section, of a portion of the device, an end view of which can be seen in Fig. 1;

Fig. 4 is a cross-sectional view of a friction coupling device forming part of the apparatus according to the invention.

Only the parts necessary for a clear understanding of the invention are shown on the drawing and these are shown, in part, schematically. Like parts are designated by like numerals in all figures of the drawing.

Referring more particularly to the drawing, tool holder It! comprises two mandrels H and I2 holding the tools, i. e. a drill and a tap, which must alternately be brought into alignment with the headstock spindle axis. The tool holder is rigidly mounted on a shaft 13 carried by bearings ql Cl-ai ms. (ores-.56)

l4 andhaving a pinion l5'fixe'd to it. The latter meshes witha toothed segment i .l 6 ,provided on the end of an armllof-atwo-piece control'lever I8, the other arm l9 of which is moved by:a pin extending into groove-2| of a cam 22. This cam' is keyed to a cam shaft-23' driven byv a worm gear 24; 25.L The-.worm125-is-loose on shaft to which astepped driving pulley 21.is fixed. ,One end of the coupling of worm 25*is provided with clams meshing with clams at; the endof a clutch sleeve 28 which is slidablealong shaft 26, to which it'is connected by means of a key29. A pin 3| extends from the end: ofa lever 42 and engages an annular groove 3|] of clutch part 28. Level 42 is fixed to a shaft 32, and anlever 33 fixed to shaft '32 bears against a p1ate34, provided on the end of a stem 35 of a plunger 36 which has a conical head, the latter being slidably mounted in a cylindrical casing 31. This casing 31 is made in one piece with the arm or cam follower part I 9 and turns with the latter about a shouldered screw-bolt 38 screwed to the arm I! as seen in Fig. 4. The pivot constituted by member 38 is eccentric with respect to the fulcrum of the lever means l1, l9.

One end of a spring 39 bears against the bottom of the casing 31, the other against the back of the head of the plunger 36, for pressing the latter into a conical recess 40 provided on arm I1 and coupling parts I! and IQ of lever [8, enabling the latter to transmit movements of pin 20 efiected by the slotted cam 22 to the pinion l5 engaged by the toothed segment 16.

Should the segment I6 be overloaded for any accidental reason, the spring 39 will yield, so that the head of the plunger 36 will be forced out of the recess 40 and the plate 34 thereby moved backwards, so that the lever 33 will be rotated in clockwise direction (Fig. 2), thereby moving part 28 in the direction of arrow M and disconnecting it from worm 25 for interrupting the drive of shaft 23 by shaft 26 and stopping the machine.

After removal of the cause of the accidental overload of segment l6, arms l1 and IQ of the control lever can be brought back to their normal positions shown on the drawing.

What I claim is:

1. A' drilling and tapping appliance for automatic lathes, comprising, in combination, an oscillating tool holder; a gear wheel connected with said holder coaxially with its oscillation axis; a cam; means for rotating said cam; lever means comprising a first part having a toothed segment in mesh with Said gear wheel, a cam follower part engaging said cam and being pivoted to said first part, and yieldable clutch means for yieldingly holding both parts in a pre-determined relative position; clutch means interposed in said means for rotating said cam for interrupting ro- 5 tation of said cam upon disengagement of said last mentioned clutch means; and engaging and disengagingmeans comiectedwith said last men.- tioned clutch means "and with said yieldable clutch means for actuation thereby. 10

2. A drilling and tapping appliance for auto=-- matic lathes, comprising, int-icombination, ana-os cillating tool holder; a gear wheelaeonnectediwitli c said holder coaxially with its oscillation axis; a cam; means for rotating said cam-glever means comprising a first part having a-ntoothemsegment- I in mesh with said gear wheel, a cam follo'werrpart engaging said cam and being pivoted to said first part eccentrically with respect to the fule'r umof said lever means, and yieldable clutch means for yieldinglv' holdingl bothipartsr in azpredetermizned relative position clutchcmeanstinterposedeiniisaid means for rotating saideam forzinter-rupting roe tat'ionfofi saidi cammpon:sdisengagement of fsaid last mentioned "clutch fmeans; and engaging-sand disengaging 'meansrconnecte'da with said last menitioned icliitchi-meansasaid :yi'eldabi clutch means comprising a memb enrbeingzdisplacedxupon dis= engagement: aofith :yieldablezclutch? means and being conneetedkwith :sai'd; engaging 52nd. disen- 0 gaging means "fonoperatiomthereofirf 3. In a drillingzandetapping:appliance fo'r-au-tm matiealathes, the-icombinationrofia -frame a-tool holder oscillatingly;suppprtedrbyrsaid:frame, a gearziwhe'eltconnectedawithilsaid tool holderrco 35 axially iwithcits oscillation raxisga cam "having: ia

groove, a drive shaft, gear means connected with said cam, a clutch disengageably connecting said drive shaft with said gear means, transmission lever means having a part swingably supported by said frame and comprising a toothed segment in mesh with said gear wheel, said transmission lever comprising a. second part pivoted to said first part f eceentrically'with respect to lithe fulcrum of *saidlever means and liavinga portion engaging said groove, a recess in one of said parts, apin connected with the other part movably in the direction-pt:its-longitudinal axis and transverselyrtorthesplane in which said lever means swings and adapted to engage said recess, and

-clutchactuating means engageable by said pin Number Name Date- 1,221,545 1 Rankin May-12221917 1,583,889 1 Larivier'el May 11,1926 1,965,714 "v Sinclair July-10,2193! 1,981,147 Moller; No'v.==20',: 1934 2,386,706 Moessinger .\Oct.'"9, 1945 2,413,031: 

